The following invention relates to an apparatus for printing labels on labeling machines with a stamping head, a rotating ink roller and a rotating inking ribbon which advances ink from an ink container to an inking roller, said inking ribbon coming into contact with the outer circumference of the inking roller.
Printing devices of this type are usually employed with labeling machines which are used with beverage filling installations. These printing devices serve, for example, to imprint filling dates or expiration dates onto the container label. This printing process can take place at the label holder, the glue palette, the gripping cylinder or directly onto the already-labeled container.
The arrangement of the printing devices on the container-filling equipment is very inconvenient with regard to maintenance procedures, since the devices can be reached only with extreme difficulty. Additionally, there is also no time for the maintenance personnel to perform any inspection work on the printing installation, since these personnel are already completely occupied with the re-supply of glue and labels. There is a demand that the printing installation not only require low maintenance, but that it also fulfill stringent requirements for quality printing.
A printing installation of the type mentioned above is known from DE-OS No. 35 30 352. With this printing installation, the inking ribbon is in the form of an endless inking ribbon which is guided over deflection rollers and which dips into an ink container located underneath the inking roller. As a result of the rotation motion of the inking ribbon, ink is carried upward and transferred to the inking roller. The inking roller is provided with a rubber coating to achieve the most uniform inking possible. Nevertheless, it sometimes happens that streaks appear on the inking roller, or areas of variable ink thickness occur, dttracting from the results of the printing. The stamping head possesses steel type which, over the course of time, indents the rubber layer on the inking roller.